Slash-and-burn agriculture is practiced across more than 60 developing countries in the tropics, with its heaviest concentration in the Amazon basin, Southeast Asia, Central Africa, Central America, and Madagascar. An estimated 300 to 500 million smallholder farmers worldwide rely on this system, making it one of the most widespread forms of subsistence farming on Earth.
The Amazon Basin
Southern Amazonia is one of the two principal global centers of slash-and-burn agriculture. Along the riverine corridors of the Amazon, shifting cultivation remains the dominant agricultural system, largely because population densities are low and fertile floodplain soils recover relatively quickly. In the middle-Amazon region, around the municipalities of Tefé and Alvarães in Brazil’s Amazonas State, smallholders clear and burn forest patches primarily to grow cassava, which is processed into cassava flour, a regional dietary staple. Tefé alone is the second-largest cassava flour producer in the state, despite having a population density of just 2.6 people per square kilometer.
What makes the Amazon distinctive is that slash-and-burn here has historically attracted less scientific attention than in Asia, precisely because the vast landscape and sparse population made the practice seem low-impact. That picture is shifting. Researchers have documented both expansion (clearing new areas) and intensification (shortening the rest period between burns), trends driven by growing rural populations and rising demand for cassava flour in urban markets.
Southeast Asia
For centuries, swidden farming stretched across nearly the entire breadth of Southeast Asia, from the highlands of southern China through mainland countries like Laos and Thailand and into the island archipelagos of Indonesia, Malaysia, and the Philippines. The practice has been central to the livelihoods of dozens of ethnic groups: Dayak communities in Borneo, Orang Asli in Peninsular Malaysia, Akha, H’mong, Lisu, and Khmu peoples in the mainland uplands, and Bataks and Tagbanua in the Philippines.
Indonesia is the other principal global hotspot alongside the Amazon. In Borneo’s West Kalimantan province, Dayak communities historically maintained complex rotational systems that included rubber gardens and fruit groves alongside their swidden fields. In northern Laos, upland landscapes were once dominated by swidden plots and fallow agroforests cultivated by Mon-Khmer and H’mong-Yao communities, while lowland valleys were reserved for paddy rice by Tai-speaking groups.
Governments across the region have aggressively discouraged or restricted the practice over the past several decades. In China’s Xishuangbanna region, where Dai, Akha, Lahu, Jinuo, and other groups all practiced shifting cultivation before 1949, state policies reshaped land use dramatically. In Sarawak (Malaysian Borneo), colonial and post-colonial governments tried to limit the territorial reach of Iban shifting cultivators, reserving forest land for logging and plantations. Indonesia’s Suharto-era government labeled swidden-practicing communities as “isolated tribes” and treated their land-use systems as backward. Many of these pressures continue today, meaning the practice is declining even in places where it was once universal.
Central Africa and the Congo Basin
The Congo Basin, spanning Cameroon, the Central African Republic, Gabon, the Republic of Congo, the Democratic Republic of Congo, and Equatorial Guinea, is the largest remaining area of tropical forest in Africa. Between 50% and 70% of the population in this region lives in rural areas close to forests, and most of these communities depend on shifting cultivation for subsistence. Firewood, charcoal production, and non-timber forest products like wild foods and medicinal plants round out their livelihoods.
Population pressure is the defining challenge here. Over the past 30 years, population density in Congo Basin countries has doubled, with more than half the population still rural and lacking basic economic and social support systems. As more people rely on the same forested land, fallow periods shorten, soil has less time to recover, and new forest is cleared more frequently.
Central America and the Milpa System
In Mesoamerica, slash-and-burn agriculture takes a distinctive cultural form known as the milpa system. Milpa is a polyculture, meaning farmers grow multiple crops together in the same cleared plot, typically maize, beans, and squash. This combination, sometimes called “the three sisters” by North American indigenous peoples, has been cultivated in the region for thousands of years. Archaeological evidence from Joya de Cerén in El Salvador, a site buried by a volcanic eruption around 600 CE, preserved croplands showing this exact three-crop association.
The milpa system is practiced today across Mexico and Central America, with particularly deep roots in the Maya region: the Yucatán Peninsula, the state of Chiapas in southern Mexico, Belize, Guatemala, and northern Honduras. Farmers clear a patch of forest or scrubland, burn the debris to release nutrients into the soil, plant their polyculture for one or two seasons, then move on and allow the plot to regrow.
Madagascar
On the island of Madagascar, off Africa’s southeastern coast, slash-and-burn agriculture (locally called “tavy”) is the primary driver of deforestation. Farmers in the dry southwestern part of the island clear forest to grow corn and other staple crops. Because Madagascar’s forests are biodiversity hotspots with extremely high rates of species found nowhere else, the environmental stakes of slash-and-burn here are disproportionately high relative to the small area involved.
How the Cycle Works
Regardless of where it is practiced, slash-and-burn follows the same basic rhythm. Farmers cut vegetation in a forested area, let it dry, and burn it. The ash delivers a pulse of nutrients, particularly nitrogen and phosphorus, into the soil, creating fertile conditions for one to three growing seasons. After yields drop, the farmer moves to a new plot and leaves the old one to regrow.
The critical variable is how long that fallow period lasts. Research on tropical soils shows that a fallow of 15 years or more after a typical two-year cropping cycle can restore soil structure, organic carbon, and nitrogen levels to conditions similar to mature native forest. A 10-year fallow helps but does not fully recover these properties. When population pressure forces farmers to shorten fallows to five or six years, the soil degrades progressively with each cycle, yields decline, and farmers must clear more forest to compensate.
Why It Persists and What Could Replace It
Slash-and-burn endures because it requires almost no purchased inputs: no fertilizer, no machinery, no irrigation. For hundreds of millions of farmers in remote tropical areas with no access to markets or agricultural extension services, it is the most practical way to feed a family. The system works well at low population densities with long fallows. It breaks down when too many people depend on too little land.
One of the most promising alternatives to emerge from field trials is a technique called Inga alley cropping, an agroforestry method where food crops are grown in alleys between rows of fast-growing Inga trees. The trees fix nitrogen from the air, their pruned branches create a thick mulch that suppresses weeds and feeds the soil, and the system can be used on the same plot year after year without burning new forest. After seven years of comparative trials testing various approaches, Inga alley cropping was the only system that showed real promise for long-term sustainability. It has since been adopted by around 300 farming families in northern Honduras, where it allows former slash-and-burn land to be converted into permanent agroforestry plots, freeing up the reserve forest that would otherwise have been burned next.